1. Field of the Invention
The present invention relates to a scanner, and more particularly, to a scanner with a guide screw rod.
2. Description of the Prior Art
With improvements in both software and hardware, scanners have begun to play an important role in importing images. Amongst the various types of scanners, desktop scanners are the most common. In a desktop scanner, a scanning module is set under a transparent surface, and moves back and forth to scan the document on the transparent surface. The scanning module does not move under its own power. Instead, a driving mechanism, such as belts or steel strings set on a plurality of wheels, is used to maintain the horizontal balance of the scanning module, to fix the direction of scanning, and to drive the scanning module back and forth. The structures of these driving mechanisms are usually complicated, making both manufacturing and maintenance of the scanner inconvenient and time-consuming. Usually, the the driving belts or steel strings can not keep the scanning module steady along a fixed path. Moreover, the driving mechanism must be driven by a motor to drive the scanning module. The power dissipation is thus large.
It is therefore an object of the present invention to provide a scanner that comprises a guide screw rod to simplify the structure of the driving mechanism. The scanning module is driven by a motor to move back and forth along the guide screw rod. The power dissipation is reduced by this arrangement.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment, which is illustrated in the various figures and drawings.